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A pteridophyte is a vascular plant (with xylem and phloem) that reproduces by means of spores. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as "cryptogams", meaning that their means of reproduction is hidden. They are also the ancestors of the plants we see today.
Ferns and lycophytes share a life cycle and are often collectively treated or studied, for example by the International Association of Pteridologists and the Pteridophyte Phylogeny Group. 23,420 species of vascular plant have been recorded in South Africa, making it the sixth most species-rich country in the world and the most species-rich ...
In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), Lycopodium is one of nine genera in the subfamily Lycopodioideae, and has from nine to 15 species. [1] [4] In other classifications, the genus is equivalent to the whole of the subfamily, since it includes all of the other genera. More than 40 species are accepted. [5]
The plants have intercalary meristems in each segment of the stem and rhizome that grow as the plant gets taller. This contrasts with most seed plants, which grow from an apical meristem - i.e. new growth comes only from growing tips (and widening of stems). Horsetails bear cones (technically strobili, sing. strobilus) at the tips of some stems.
Additionally 1674 plant species (7.6% of those evaluated) are listed as data deficient, meaning there is insufficient information for a full assessment of conservation status. As these species typically have small distributions and/or populations, they are intrinsically likely to be threatened, according to the IUCN. [ 2 ]
Polypodiaceae is a family of ferns.In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), the family includes around 65 genera and an estimated 1,650 species and is placed in the order Polypodiales, suborder Polypodiineae. [1]
In 2016, the Pteridophyte Phylogeny Group divided order Polypodiales into six suborders. Pteridaceae is the sole family in suborder Pteridiineae, with 52 genera. The suborder has the same circumscription as Smith et al. used for the family. The phylogenetic relationship between these six suborders is shown in this cladogram: [2]
Pteris (brake) is a genus of about 300 species of ferns in the subfamily Pteridoideae of the family Pteridaceae. [1] [2] They are native to tropical and subtropical regions, southward to New Zealand, Australia, and South Africa, north to Japan and North America. 78 species (35 endemic) are found in China. [3]